TDR research on vector control and ecosystem management

Ecosystem management to prevent dengue and Chagas disease

Dengue fever is one of the most rapidly growing epidemics in the world. The proximity of vector breeding sites to households and household water containers is a major factor in the transmission of both dengue fever and Chagas disease. See TDRnews 77 [pg 7 ]

A range of other ecological, biological and social factors also tend to promote disease transmission or inhibit efforts at vector control:

  • Natural factors include climate (rainfall, humidity, temperature etc). Development of urban settlements and agriculture also have a profound impact.
  • Biological factors relate to the behaviour of the dengue vector, Aedes aegypti, and the transmission dynamics of the disease.
  • Social factors include vector control and health services, water and sanitation services, and community and household based practices (such as those related to garbage disposal and sanitation).

TDR, in partnership with the International Development and Research Centre (IDRC), is leading multidisciplinary studies on ecosystem management of vector-borne diseases such as dengue and Chagas disease in Asia and Latin America.

  • The six country study in Asia and southeast Asia, Eco-Bio-Social Research on Dengue in Asia, is in its second phase.
  • A study in nine sites in Latin America and the Caribbean, Community-based Ecosystem Management Interventions for Improved Dengue and Chagas Disease Prevention, is now beginning.
  • An initial pilot study in Colombia and Brazil, Eco-Bio-Social Aspects of Dengue, was completed in 2005.

Eco-Bio-Social Research on Dengue in Asia

This two-phase research project aims to improve dengue prevention through better understanding and health sector actions related to ecological, biological and social factors. The first phase of the study examined ecological, biological and social factors in the transmission dynamics of dengue in six community settings in India, Indonesia, Myanmar, the Philippines, Sri Lanka and Thailand. The second phase of the study is developing interventions based on the findings from the initial phase. For instance, research teams are examining how the use of natural predators and biological larvicides such as dragonfly nymphs and Bacillus thuringiensis serovar israelensis (Bti), as well as water covers, window curtains and waste control measures, may reduce vector densities. Teams are also examining how communities become involved and support the activities. The initiative, funded by the EcoHealth Programme of IDRC, involves multi-disciplinary research teams at universities and research centres.

For more about this research see: TDRnews 82 on launch of the second phase of activities.

Community-based ecosystem management for improved dengue and Chagas disease prevention

Launched in October 2008, this is TDR's most recent eco-bio-social research initiative in partnership with IDRC. Ten research sites focusing on dengue and Chagas disease are being developed in low-to-middle income countries (LMICs) of Latin America and the Carribbean.

The first phase of research aims to improve dengue and Chagas disease prevention through multi-level/multi-scale and transdisciplinary analysis of ecosystem-related, biological and social factors. This will be followed by the Phase II development of community-directed public health interventions targeting dengue and Chagas disease vector larval habitats.

Eco-bio-social aspects of dengue prevention

This was the initial TDR/IDRC pilot programme on eco-bio-social research. It responded to the resurgence of dengue fever in Latin America. Studies in two sites were completed in 2005. Findings have been published in a special issue of the Latin American health journal Cadernos de Saude Publica.

The study in Colombia was conducted under the leadership of the Fundacion Santa Fé de Bogota, in collaboration with the Universidad de los Andes, the Universidad del Valle and the Colombian National Institute of Health. The study investigated the dengue problem in two endemic cities on the Magdalena river basin. A trans-disciplinary team included epidemiologists, anthropologists, meteorologists and social researchers. Articles included in the special volume of Cadernos include:

An ecosystemic approach to evaluating ecological, socioeconomic and group dynamics affecting the prevalence of Aedes aegypti in two Colombian towns.

Quintero, J, Carrasquilla, G., Suárez, R, González, C, Olano, VA

An ecosystem perspective in the socio-cultural evaluation of dengue in two Colombian towns.

Suárez, R., González, C., Carrasquilla, G., Quintero, J

The study in Brazil was led by the Ceará State University. It described eco-bio-social factors responsible for the re-emergence of dengue fever in the Brazilian city of Fortaleza, through a combination of survey research, entomological assessments and ethnographic research.

Irregular water supply, household usage and dengue: a bio-social study in the Brazilian Northeast.

Caprara, A., Lima, José Wellington de Oliveira; Marinho, ACP., Calvasina, PG., Landim, LP., Sommerfeld, J